Printing device and printing method

ABSTRACT

The present invention provides an information printing method and a printing device, which assure a higher level of security when outputting printed matter. The present invention provides a printing device comprising a document storage means for storing electronic document data generated at a printing instruction issuing terminal operated by a printing instruction issuer and transmitted from the printing instruction issuing terminal, an ID setting means for setting a print retriever ID of a print retriever who is to execute processing for outputting the electronic document data stored at the document storage means onto paper, a watermark information superimposing means for superimposing the print retriever ID having been set at the ID setting means as watermark information onto the electronic document data and a printing means for outputting the electronic document data having the watermark information superimposed thereupon by the watermark information superimposing means onto paper.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.11/585,094, which was filed on Oct. 24, 2006 and allowed on Jul. 5,2012, and which claims priority from Japanese Patent Application No. JP2005-318999, filed on Nov. 2, 2005, the disclosure of which, includingthe specification, drawings and abstract, is incorporated herein byreference in its entirety

BACKGROUND OF THE INVENTION

The present invention relates to a printing method and a printingdevice.

Information leakage via important printed documents such as confidentialcommunications having been printed on a printing device such as aprinter, which is left untended and ends up in the hands of athird-party, has been occurring with increasing frequency. The problemis exacerbated by the difficulty in identifying the source of the leakedprinted matter on which information enabling identification of theperson who has printed out the document is not superimposed in anindelible format.

The problem is addressed in the invention disclosed in Japanese LaidOpen Patent Publication No. 2003-101762 related to a printing method anda printing device achieved by adopting a technology whereby watermarkinformation is superimposed on electronic document data so as to printout the electronic document data by automatically superimposinginformation indicating the printing party, the printing date or the like(see Japanese Laid Open Patent Publication No. 2003-101762).

However, even the method disclosed in Japanese Laid Open PatentPublication No. 2003-101762 does not provide a complete solution to theproblem. Namely, if the terminal at which the printing party issues aprinting instruction is located over a considerable distance from theprinting device on which the printed matter is output, a third-party maytake away the printed matter output on paper before the printing partyhaving issued the printing instruction reaches the printing device.Under such circumstances, it will be difficult to track the printedmatter.

SUMMARY OF THE INVENTION

Accordingly, an object of the present invention, which has beencompleted by addressing the problems of the related art discussed above,is to provide an information printing method and a printing device thatassure a high level of security when outputting printed matter on aprinting device by superimposing information indicating the printedmatter outputting party over the electronic document data.

The object described above is achieved in an aspect of the presentinvention by providing a printing device that prints out electronicdocument data by superimposing watermark information over the electronicdocument data, comprising a document storage means for storingelectronic document data generated at a printing instruction issuingterminal operated by a printing instruction issuer who has issued aninstruction for printing an electronic document and transmitted from theprinting instruction issuing terminal, an ID setting means for setting aprint retriever ID of a print retriever who is to engage the printingdevice in processing for outputting the electronic document data storedat the document storage means onto paper as printed matter, a watermarkinformation superimposing means for superimposing the print retriever IDhaving been set at the ID setting means as watermark information ontothe electronic document data stored at the document storage means and aprinting means for outputting the electronic document data having thewatermark information superimposed thereupon by the watermarkinformation superimposing means onto paper as printed matter.

In the printing device adopting the structure described above, thedocument storage means stores the electronic document data generated atthe printing instruction issuing terminal, the ID setting means sets theprint retriever ID indicating the print retriever to execute theprocessing for outputting the electronic document data as printed matteronto paper, the watermark information superimposing means superimposesthe information indicating the print retriever ID as watermarkinformation onto the electronic document data and the printing meansoutputs the electronic document data having superimposed thereupon thewatermark information onto paper as printed matter. In other words,information indicating the person who has actually output the printedmatter on the printing device can be superimposed as watermarkinformation onto the printed matter by employing the printing deviceachieved in the first aspect of the present invention.

The ID setting means may wait in standby without setting the printretriever ID until after the electronic document data are transmittedfrom the printing instruction issuing terminal and the electronicdocument data are stored into the document storage means and,accordingly, the watermark information superimposing means maysuperimpose watermark information indicating the print retriever ID overthe electronic document data only after the ID setting means sets theprint retriever ID. In other words, the ID setting means may enter astate in which the print retriever ID is set only after the electronicdocument data are stored into the document storage means and only thenthe watermark information superimposing means may superimpose watermarkinformation indicating that print retriever ID having been set by the IDsetting means. In this case, since the ID setting means sets the printretriever ID after the print processing is executed at the printinginstruction issuing terminal, the printed matter can be output with aneven higher level of security.

The printing device may further comprise a document selection means forselecting the electronic document data to be output as printed matteronto paper among sets of electronic document data stored at the documentstorage means. The watermark information superimposing means in such aprinting device may superimpose the watermark information indicating theprint retriever ID set via the ID setting means over the electronicdocument data having been selected by the document selection means. Inthe printing device, the document selection means selects the electronicdocument data to be output from the sets of electronic document datastored at the document storage means and the watermark informationindicating the print retriever ID set via the ID setting means issuperimposed over the selected electronic document data. This structureallows a plurality of sets of electronic document data to be stored atthe document storage means.

The document storage means may further store authorization informationindicating paper output authorization in a format that correlates theauthorization information to the electronic document data. In thisprinting device, only after the ID setting means sets the printretriever ID, can the document selection means make a decision as towhether or not the person corresponding to the print retriever ID isauthorized to output the electronic document data onto paper as printedmatter, and only after the person corresponding to the print retrieverID is judged to be authorized to output the electronic document dataonto paper as printed matter, can the watermark informationsuperimposing means superimpose the print retriever ID as a watermarkover the electronic document data. In this case, only when the personcorresponding to the print retriever ID is authorized to retrieve theprinted matter, the print retriever ID is superimposed on the electronicdocument data as a watermark. As a result, unless the personcorresponding to the print retriever ID is authorized to retrieve theprinted matter, the electronic document data output cannot be extractedfrom the printing device. Alternatively, if the person corresponding tothe print retriever ID is not authorized to output the electronicdocument data onto paper as printed matter, the electronic document datamay be destroyed.

The authorization for paper output indicated in the authorizationinformation may be an attribute included therein that matches anattribute of the print retriever ID. In this case, only if theauthorization information indicating the paper output authorizationincludes an attribute of the print retriever ID, the print retriever IDis superimposed over the electronic document data as a watermark. As aresult, unless the authorization information indicating the paper outputauthorization includes an attribute of the print retriever ID, theelectronic document data cannot be extracted from the printing device.

The authorization for paper output indicated in the authorizationinformation may be an ID included therein that matches the printretriever ID. In this case, if the authorization information indicatingthe paper output authorization includes an ID matching the printretriever ID, the print retriever ID can be superimposed on theelectronic document data as a watermark. In other words, unless theauthorization information indicating paper output authorization includesan ID matching the print retriever ID, the electronic document datacannot be extracted from the printing device.

The watermark information superimposing means may further superimposeover the electronic document data watermark information indicating atleast one of; the date/time at which the printing instruction is issuedby the printing instruction issuer, the name of the printing instructionissuer, the document title assigned to the electronic document data, theterminal name of the printing instruction issuing terminal, and the IPaddress of the printing instruction issuing terminal or informationenabling identification of the printing device. The information thatenables identification of the printing device may be the serial numberassigned to the printing device or an ID designated to the printingdevice. The watermark information superimposing means adopting thisstructure superimposes information used to identify the electronicdocument data or the printing device as watermark information inaddition to the print retriever ID set via the ID setting means. As aresult, since information that enables identification of the electronicdocument data or the printing device is superimposed as watermarkinformation onto the printed matter, it is possible to later ascertainthe specific date/time and the specific location at which the electronicdocument data were output, in addition to the specific person thatexecuted the output processing.

If the ID setting means does not set the print retriever ID within apredetermined length of time, the electronic document data stored at thedocument storage means may be discarded. In this case, if the printretriever ID is not set within the predetermined length of time afterthe electronic document data are transmitted from the printinginstruction issuing terminal to the printing device, the electronicdocument data stored at the document storage means are discarded. As aresult, since the electronic document data are not stored at thedocument storage means over an indeterminate length of time, theconfidential document is handled with a high level of security.

The ID setting means may be a card reader. Such an ID setting means setsthe print retriever ID by reading an ID card via the card reader. Inother words, the print retriever ID can be set by using an ID card.

The ID setting means may instead be constituted with a biometricverification device. In this case, the ID setting means sets the printretriever ID via the biometric verification device. As a result, anunauthorized third-party cannot falsely claim to be authorizedpersonnel.

The object described above is achieved in another aspect of the presentinvention by providing a watermark information superimposing device thatsuperimposes watermark information on electronic document data inprinting applications, comprising a document storage means for storingelectronic document data generated at a printing instruction issuingterminal operated by a printing instruction issuer who has issued aninstruction for printing an electronic document and transmitted from theprinting instruction issuing terminal, an ID setting means for setting aprint retriever ID of a print retriever who is to execute processing foroutputting the electronic document data stored at the document storagemeans onto paper as printed matter and a watermark informationsuperimposing means for superimposing the print retriever ID having beenset at the ID setting means as watermark information onto the electronicdocument data. The watermark information superimposing device ischaracterized in that the ID setting means wait in standby withoutsetting the print retriever ID until after the electronic document dataare transmitted from the printing instruction issuing terminal and theelectronic document data are stored into the document storage means andthat the watermark information superimposing means superimposes theprint retriever ID onto the electronic document data as watermarkinformation only after the ID setting means sets the print retriever ID.

In the watermark information superimposing means adopting the structuredescribed above, the document storage means stores the electronicdocument data generated at the printing instruction issuing terminal,the ID setting means sets the print retriever ID indicating the printretriever to execute the processing for outputting the electronicdocument data as printed matter onto paper and the watermark informationsuperimposing means superimposes information indicating the printretriever ID as watermark information onto the electronic document data.In other words, information indicating the person who has actuallyattempted to output the electronic document data via the printing devicecan be superimposed as watermark information onto the printed matter byemploying the watermark information superimposing device achieved in thesecond aspect of the present invention.

The object described above is further achieved in yet another aspect ofthe present invention by providing a printing method to be adopted in aprinting device, comprising steps for storing electronic document datagenerated at a printing instruction issuing terminal operated by aprinting instruction issuer having issued an instruction for printingout an electronic document, setting at the printing device a printretriever ID of a print retriever to retrieve the electronic documentdata from the printing device, superimposing the print retriever ID overthe electronic document data as a watermark at the printing device onlyafter the print retriever ID is set and outputting the electronicdocument data having superimposed thereupon the watermark onto paper asprinted matter at the printing device.

The printing device adopting the printing method described abovesuspends print processing until after the print retriever ID is set andonce the print retriever ID is set, the printing device superimposes theprint retriever ID onto the electronic document data as watermarkinformation and outputs the electronic document data onto paper asprinted matter. Thus, the printing method adopted in the printingdevice, as achieved in the third aspect of the present invention, makesit possible to obtain from the printed matter information indicating theprint retriever who has actually output the electronic document datathrough the printing device.

The object described above is also achieved in a still further aspect ofthe present invention by providing a printing method to be adopted in aprinting device, comprising steps for storing electronic document datagenerated at a printing instruction issuing terminal operated by aprinting instruction issuer who issues an instruction for printing outdocument data and containing a printing instruction issuer ID, settingat the printing device a print retriever ID indicating a print retrieverto retrieve the electronic document data from the printing device,making a decision as to whether or not the person corresponding to theprint retriever ID is authorized to retrieve the electronic documentdata from the printing device only after the print retriever ID is set,superimposing the print retriever ID onto the electronic document dataas a watermark at the printing device only if the person correspondingto the print retriever ID is judged to be authorized to retrieve theelectronic document data from the printing device and outputting theelectronic document data having superimposed thereupon the watermarkonto paper as printed matter at the printing device.

In this case, the printing device adopting the printing method suspendsprint processing until after the print retriever ID is set, and once theprint retriever ID is set, the printing device superimposes the printretriever ID onto the electronic document data as watermark informationand outputs the electronic document data onto paper as printed matteronly if the person corresponding to the print retriever ID is judged tobe authorized to retrieve the electronic document data from the printingdevice. Thus, the printing method adopted in the printing device, asachieved in the fourth aspect, ensures that the electronic data can beoutput as printed matter only if the print retriever is authorized toretrieve the electronic document data via the printing device and thatinformation indicating the print retriever who has actually output theelectronic document data on the printing device can be obtained as thewatermark information superimposed on the printed matter.

The decision as to whether or not the person corresponding to the printretriever ID is authorized to retrieve the electronic document data fromthe printing device may be made by judging whether or not the printinginstruction issuer ID and the print retriever ID match. In this case,only if the printing instruction issuer ID matches the print retrieverID, the electronic document data can be output as printed matter. Thus,the electronic document data can be output as printed matter only if theprint retriever coincides with the printing instruction issuer havingissued the instruction for printing out the document. In addition,information indicating that print retriever who has actually output theelectronic document data via the printing device can be obtained as thewatermark information superimposed over the printed matter.

The decision as to whether or not the person corresponding to the printretriever ID is actually authorized to retrieve the electronic documentdata from the printing device may be made by judging whether or notauthorization information indicating authorization for paper outputincludes an attribute of the print retriever ID. In such a case, unlessthe authorization information indicating the paper output authorizationincludes an attribute of the print retriever ID, the electronic documentdata cannot be output as printed matter. As a result, the printretriever is able to output printed matter only if the print retrieverID includes the authorization information indicating the paper outputauthorization. Furthermore, the information indicating the printretriever who has actually output the electronic document data from theprinting device can be obtained as the watermark informationsuperimposed on the printed matter. In addition, the paper outputauthorization information may indicate a specific party indicated by theprinting instruction issuer to be authorized to output the electronicdocument data on paper, or authorization information indicating viewingauthorization, printing authorization or the like held in a databasesystem where document data are stored may be used as the authorizationinformation to allow only a party authorized in the database system toperform a printing operation to retrieve the printed matter.

The present invention provides an information printing method and aprinting device that allow printed matter to be output with a higherlevel of security by superimposing information indicating a party havingoutput the printed matter via a printing device onto electronic documentdata.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the structure adopted in the first embodiment of thepresent invention;

FIG. 2 is a block diagram of the first embodiment of the presentinvention;

FIG. 3 presents a flowchart of the processing executed in the firstembodiment of the present invention;

FIG. 4 shows the structure adopted in the second embodiment of thepresent invention;

FIG. 5 is a block diagram of the second embodiment of the presentinvention; and

FIG. 6 presents a flowchart of the processing executed in the secondembodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following is a detailed explanation of the preferred embodiments ofthe present invention, given in reference to the attached drawings. Itis to be noted that in the specification and the drawings, the samereference numerals are assigned to components having substantiallyidentical functions and structural features to preclude the necessityfor a repeated explanation thereof.

First Embodiment

FIGS. 1 and 2 provide diagrams in reference to which the printing deviceand the printing method achieved in the first embodiment of the presentinvention are explained. As shown in FIGS. 1 and 2, the printing methodin the first embodiment of the present invention is implemented inconjunction with a printing instruction issuing terminal 110 and aprinting device 120.

The printing instruction issuing terminal 110 includes a pagedescription language conversion means 112. The page description languageconversion means 112, which converts an original document created in adocument creating program such as a word processing program or anediting program to electronic document data 150 adopting a pagedescription language format that can be read by the printing device, isnormally realized in the form of a software program such as a printerdriver. While the existing page description languages includePostScript, HP-PCL and LIPS, any of these page description languages maybe used in the embodiment.

The printing device 120 comprises a document storage means 122, a basepattern generation means 126 functioning as a watermark informationsuperimposing means, a printing means 128 and an ID setting means 130.

At the document storage means 122, the electronic document data 150having been generated at the printing instruction issuing terminal 110are temporarily stored. The document storage means 122 may beconstituted with a hard disk drive or a large-capacity memory. While thedocument storage means 122 in the embodiment is built into the printingdevice 120, the document storage means 122 according to the presentinvention does not need to be provided as a built-in unit in theprinting device 120 and may instead be constituted with a hard diskdrive or a large-capacity memory provided as an outside unit directlyconnected to the printing device 120 or connected to the printing device120 via a network. In other words, the document storage means 122 mayassume a mode such as a document server connected to the printing device120.

The ID setting means 130 sets a print retriever ID indicating a printretriever to retrieve the electronic document data from the printingdevice 120 as printed matter containing the electronic document dataprinted out on paper. The print retriever ID is set in this embodimentby entering at the printing device information that enablesidentification of the print retriever. The ID setting means 130 may beconstituted with a numeric keypad provided at the printing device, acard reader capable of reading an ID card of the print retriever, or abiometric verification device that biometrically verifies the printretriever. Either a contact-type card reader or a noncontact-type cardreader may be used as the ID setting means. In addition, the ID settingmeans 130 may constitute an integrated part of the printing device or itmay be an outside unit connected to the printing device. The ID settingmeans 130 provided as an outside unit may be connected to the printingdevice either through wired connection or through wireless connection.The ID setting means 130 in the embodiment is constituted with amagnetic card reader provided as an integrated part of the printingdevice 120. As a magnetic ID card 140 belonging to the print retrieveris inserted at the magnetic card reader, the print retriever ID of theprint retriever can be set.

The base pattern generation means 126 generates a base pattern basedupon information indicating the print retriever ID set via the IDsetting means 130, the printing time or the like and superimposes thebase pattern as watermark information over the electronic document data.The data superimposed as the watermark information may includeinformation used to identify the electronic document data, such asinformation indicating the document title of the electronic documentdata, the name of the printing instruction issuer, the name of theprinting instruction issuing terminal or the IP address of the printinginstruction issuing terminal, in addition to the information indicatingthe print retriever ID or the printing time. In addition, informationthat enables identification of the printing device 120, e.g., the serialnumber assigned to the printing device 120 or an ID pre-designated tothe printing device 120, may be superimposed as the watermarkinformation. While the base pattern generation means 126 is provided asa built-in unit in the printing device 120 in the embodiment, the basepattern generation means 126 according to the present invention mayinstead be provided as an outside unit directly connected to theprinting device 120 or connected to the printing device 120 via anetwork.

The watermark information may be superimposed over the electronicdocument data by adopting the technology disclosed in Japanese Laid OpenPatent Publication No. 2003-101762 whereby a base pattern is generatedand is superimposed over electronic document data or by adopting atwo-dimensional barcode technology. However, since a two-dimensionalbarcode can easily be removed by cutting it off from the printed matteron which it is printed or by painting over it, it is desirable to adoptthe method disclosed in Japanese Laid Open Patent Publication No.2003-101762 whereby the watermark information is superimposed on theelectronic document data by generating a base pattern, i.e., by usingthe so-called Val-Code (registered trademark) so as to effectivelyprevent information leaks.

The base pattern generation method adopted in the embodiment is brieflyexplained. Information to be used as the watermark information is firstconverted to an N-dimensional code (N is a given integer). For instance,the printing instruction issuer ID may be converted to a two-dimensionalcode. Next, a watermark signal is assigned to each of the symbolsconstituting the coding language. A watermark signal expresses a wavewith a given wavelength and given directionality through a dot array.Next, a watermark image to be used as the watermark information isgenerated by arranging a signal unit corresponding to the bit string ofthe coded data. The term “signal unit” in this context refers to asingle signal unit assuming a rectangular shape having the width and theheight of the watermark signal.

The printing means 128 outputs the electronic document data 150 havingsuperimposed thereupon the base pattern to be used as the watermarkinformation, which has been generated at the base pattern generationmeans 126, as printed matter onto paper. The electronic document datamay be printed out onto the paper in a single color or in multiplecolors.

FIG. 3 presents a flowchart of the print processing executed in thefirst embodiment of the present invention.

First, the printing instruction issuer executes original document printprocessing from the printing instruction issuing terminal 110 (stepS102). The print processing may be executed by using the printingfunction of the word processing software program or the editor programoperated at the printing instruction issuing terminal 110.

As the original document print processing is executed at the printinginstruction issuing terminal 110, the page description languageconversion means 112 converts the original document into data written ina page description language that can be read by the printing device 120and the electronic document data 150 resulting from the conversion aretransmitted to the printing device 120 (step S104).

The electronic document data 150 thus transmitted are temporarily storedinto the document storage means 122 at the printing device 120 (stepS106).

Once the electronic document data 150 are stored into the documentstorage means 122, the printing device 120 waits in standby over apredetermined length of time for the print retriever ID to be set viathe ID setting means 130 (step S108).

If the print retriever ID is entered through the ID setting means 130within the predetermined length of time, the print retriever ID is set(step S110), and the base pattern generation means 126 executesprocessing for superimposing the print retriever ID having been set overthe electronic document data 150 as a base pattern (step S112). If theelectronic document data 150 having been transmitted from the printinginstruction issuing terminal 110 include information indicating specificprinting conditions such as the document title assigned to theelectronic document data 150, the name of the printing instructionissuer, the name of the printing instruction issuing terminal or the IPaddress of the printing instruction issuing terminal, informationindicating at least one of the printing conditions may be superimposedas the base pattern in step S112. In addition, information that enablesidentification of the printing device 120, such as the serial numberassigned to the printing device 120 or the printing device IDpre-assigned to the printing device 120, may instead be superimposed asthe base pattern constituting the watermark information.

The electronic document data 150 having superimposed thereupon the basepattern are then output onto paper via the printing means 128 (stepS114). Once the electronic document data 150 are output onto the paper,the print processing ends.

If, on the other hand, no print retriever ID is set in step S108, adecision is made as to whether or not the predetermined length of timehas elapsed (step S116). If it is decided that the predetermined lengthof time has not elapsed, the operation returns to step S108 to wait instandby for the print retriever ID to be set via the ID setting means130. If no print retriever ID is set via the ID setting means 130 afterthe predetermined length of time elapses, the electronic document data150 are discarded (step S118) and the processing ends. The electronicdocument data 150 are discarded in step S118 as described above so as tobetter protect the confidentiality of the electronic document data 150.However, the electronic document data 150 may remain stored at thedocument storage means 122 when the predetermined length of timeelapses, instead of being discarded.

As described above, the first embodiment of the present inventionprovides a printing device and a printing method that make it possibleto identify the party who has actually output the printed matter fromthe printing device by superimposing on the output document informationindicating the party who has retrieved the printed matter from theprinting device.

Second Embodiment

FIGS. 4 and 5 provide diagrams in reference to which the printing deviceand the printing method achieved in the second embodiment of the presentinvention are explained. As shown in FIGS. 4 and 5, the printing methodin the second embodiment of the present invention is also implemented inconjunction with a printing instruction issuing terminal 210 and aprinting device 220, as in the case of the printing method in the firstembodiment

The printing instruction issuing terminal 210 includes a pagedescription language conversion means 212 and a printing instructionissuer ID setting means 214.

The page description language conversion means 212, which converts anoriginal document to data written in a page description language thatcan be read by the printing device, is normally realized in the form ofa software program such as a printer driver, as is the page descriptionlanguage means in the first embodiment. While the existing pagedescription languages include PostScript and HP-PCL, either of thesepage description languages may be used in the embodiment.

The printing instruction issuer ID setting means 214 sets a printinginstruction issuer ID 260 which is used as information for identifyingthe printing instruction issuer. The log-in user at the printinginstruction issuing terminal may be set as the printing instructionissuer ID 260. Alternatively, the printing instruction issuer ID may beset by using a card reader connected to the printing instruction issuingterminal 210 to read an ID card owned by the printing instruction issueror by entering the printing instruction issuer ID 260 through a keyboardtogether with a printing instruction. In addition, the user entering theprinting instruction issuer ID 260 may also be asked to enter apassword. The password thus entered may then be transmitted to theprinting device together with the electronic document data 250.

The printing device 220 comprises a document storage means 222, adocument selection means 224, a base pattern generation means 226 tofunction as a watermark information superimposing means, a printingmeans 228 and a print retriever ID setting means 230.

At the document storage means 222, the electronic document data 250generated at the printing instruction issuing terminal 210 aretemporarily stored. The document storage means 222 may be constitutedwith a hard disk drive or a large-capacity memory. While the documentstorage means 222 in the embodiment is built into the printing device220, as in the first embodiment, the document storage means 222according to the present invention does not need to be provided as abuilt-in unit in the printing device 220 and may instead be constitutedwith a hard disk drive or a large-capacity memory provided as an outsideunit directly connected to the printing device 220 or connected to theprinting device 220 via a network. In other words, the document storagemeans 222 may assume a mode such as a document server connected to theprinting device 220.

The print retriever ID setting means 230 sets a print retriever IDindicating a print retriever to retrieve the electronic document datafrom the printing device 220 as printed matter containing the electronicdocument data printed out on paper. The print retriever ID is set inthis embodiment by entering information that enables identification ofthe print retriever. The print retriever ID setting means 230 may beconstituted with a numeric keypad provided at the printing device, acard reader capable of reading an ID card of the print retriever, or abiometric verification device that biometrically verifies the printretriever. Either a contact-type card reader or a noncontact-type cardreader may be used as the ID setting means. In addition, the printretriever ID setting means 230 may constitute an integrated part of theprinting device 220 or it may be an outside unit connected to theprinting device 220. The print retriever ID setting means 230 providedas an outside unit may be connected to the printing device 220 eitherthrough wired connection or wireless connection. The print retriever IDsetting means may allow password entry, as well. The print retriever IDsetting means 230 in the embodiment is constituted with a magnetic cardreader provided as an integrated part of the printing device 220, as inthe first embodiment. As a magnetic ID card 240 belonging to the printretriever is inserted at the magnetic card reader, the print retrieverID of the print retriever can be set.

The document selection means 224 selects a specific set of electronicdocument data to be output onto paper as printed matter from sets ofelectronic document data stored at the document storage means 222. Thedocument selection means 224 also makes a decision as to whether or notthe print retriever with the print retriever ID having been set via theprint retriever ID setting means 230 is authorized to retrieve via theprinting device 220 the electronic document data stored at the documentstorage means 222.

The decision as to whether or not the print retriever has been grantedretrieval authorization may be made by judging whether or not the printretriever ID matches the printing instruction issuer ID. Alternatively,an authorized print retriever ID indicating an authorized printretriever allowed to output the electronic document data onto paper viathe printing device may be appended to the electronic document datatogether with the printing instruction issuer ID and the decision as towhether or not the print retriever is authorized to retrieve the printmay be made by judging whether or not the print retriever ID matcheseither the printing instruction issuer ID or the authorized printretriever ID.

Alternatively, information indicating an attribute of the printretriever who is allowed to retrieve the electronic document data asprinted matter may be appended to the electronic document data togetherwith the printing instruction issuer ID and the decision as to whetheror not the print retriever has the retrieval authorization may be madeby judging whether or not the attributes of the print retrievercorresponding to the print retriever ID having been set include theprint retriever attribute transmitted from the printing instructionissuing terminal. These attributes assume a hierarchical structure, anda higher-order attribute includes lower-order attributes. For instance,assuming that an attribute “section manager” is set in correspondence tothe printing instruction issuer and that an attribute “departmentmanager” is set in correspondence to the print retriever, the printretriever with the higher-order attribute is authorized to retrieve thecorresponding electronic document data. If, on the other hand, theattribute “department manager” is set for the printing instructionissuer and the attribute “section manager” is set for the printretriever, the print retriever with the lower-order attribute is notauthorized to retrieve the corresponding electronic document data.

If a password having been entered at the printing instruction issuingterminal is transmitted together with the electronic document data fromthe printing instruction issuing terminal so as to allow the password tobe set at the print retriever ID setting means 230, the documentselection means 224 may make a decision as to whether or not the printretriever has output authorization by judging whether or not thepassword having been set by the printing instruction issuer matches thepassword set by the print retriever.

The base pattern generation means 226 generates a base pattern basedupon information indicating the print retriever ID set via the printretriever ID setting means 230, the printing time or the like andsuperimposes the base pattern as watermark information onto theelectronic document data 250. The data superimposed as the watermarkinformation may include information indicating the printing conditions,such as the document title of the electronic document data, the name ofthe printing instruction issuer, the name of the printing instructionissuing terminal or the IP address of the printing instruction issuingterminal, in addition to the information indicating the print retrieverID or the printing time. In addition, information that enablesidentification of the printing device 220, e.g., the serial numberassigned to the printing device 220 or an ID pre-designated to theprinting device 220, may be superimposed as the watermark information.While the base pattern generation means 226 in this embodiment, too, isprovided as a built-in unit in the printing device 220 as in the firstembodiment, the base pattern generation means 226 may instead beprovided as an outside unit directly connected to the printing device220 or connected to the printing device 220 via a network.

The watermark information may be superimposed over the electronicdocument data by adopting the technology disclosed in Japanese Laid OpenPatent Publication No. 2003-101762 whereby a base pattern is generatedand is superimposed over electronic document data or a two-dimensionalbarcode technology, as in the first embodiment. However, since atwo-dimensional barcode can easily be removed by cutting it off from theprinted matter on which it is printed or by painting over it, it is moredesirable to adopt the method disclosed in Japanese Laid Open PatentPublication No. 2003-101762 whereby the watermark information issuperimposed on the electronic document data by generating a basepattern, i.e., by using the so-called Val-Code (registered trademark) soas to effectively prevent information leaks. Since the base patterngeneration method adopted in the embodiment is identical to that adoptedin the first embodiment, its explanation is omitted.

The printing means 228 outputs the electronic document data 250 havingsuperimposed thereupon the base pattern to be used as the watermarkinformation, which has been generated at the base pattern generationmeans 226, as printed matter onto paper. The electronic document datamay be printed out onto the paper in a single color or in multiplecolors.

FIG. 6 presents a flowchart of the processing executed in the secondembodiment of the present invention.

First, the printing instruction issuer executes original document printprocessing from the printing instruction issuing terminal 210 (stepS202). The print processing may be executed by using the printingfunction of the word processing software program or the editor programoperated at the printing instruction issuing terminal 210.

As the original document print processing is executed at the printinginstruction issuing terminal 210, the page description languageconversion means 212 converts the original document into data written ina page description language that can be read by the printing device 220and the electronic document data at 250 resulting from the conversionare transmitted to the printing device 220 (step S204). When theelectronic document data are transmitted, the printing instructionissuer ID having been set at the printing instruction issuer ID settingmeans 214 is appended to the electronic document data 250 transmitted tothe printing device 220.

The electronic document data 250 thus transmitted are temporarily storedinto the document storage means 222 at the printing device 220 (stepS206).

Once the electronic document data 250 are stored into the documentstorage means 222, the printing device 220 waits in standby over apredetermined length of time for the print retriever ID to be set viathe print retriever ID setting means 230 (step S208).

If the print retriever ID is entered through the print retriever IDsetting means 230 within the predetermined length of time, the documentselection means 224 makes a decision as to whether or not the personcorresponding to the print retriever ID is authorized to retrieve theelectronic document data 250 (step S210).

If the person corresponding to the print retriever ID having been set isauthorized to retrieve the electronic document data 250, the documentretriever ID is set (step S212), and the base pattern generation means226 executes processing for superimposing the print retriever ID havingbeen set over the electronic document data 250 as a base pattern (stepS214). If the electronic document data 250 having been transmitted fromthe printing instruction issuing terminal 210 include informationindicating specific printing conditions such as the document titleassigned to the electronic document data, the name of the printinginstruction issuer, the name of the printing instruction issuingterminal or the IP address of the printing instruction issuing terminal,information indicating at least one of the printing conditions may besuperimposed as the base pattern. In addition, information that enablesidentification of the printing device 220, such as the serial numberassigned to the printing device 220 or the printing device IDpre-assigned to the printing device 220, may be superimposed as thewatermark information.

The electronic document data 250 having superimposed thereupon the basepattern are then output onto paper via the printing means 228 (stepS216). Once the electronic document data 250 are output onto the paper,the print processing ends.

If, on the other hand, no print retriever ID is set in step S208, adecision is made as to whether or not the predetermined length of timehas elapsed (step S218). If it is decided that the predetermined lengthof time has not elapsed, the operation returns to step S208 to wait instandby for the print retriever ID to be set. If no print retriever IDis set after the predetermined length of time elapses, the electronicdocument data are discarded (step S220) and the processing ends.

If it is decided in step as 210 that the person corresponding to theprint retriever ID having been set is not authorized for electronicdocument data retrieval, the electronic document data are discarded(steps S 220) to assure a higher level of security and the processingthen ends.

The electronic document data 250 are discarded in step S220 so as toenhance the protection for the confidentiality of the electronicdocument data 250. However, even after the predetermined length of timeelapses or even when the person corresponding to the print retriever IDhaving been set is not authorized to retrieve the electronic documentdata, the electronic document data 250 do not need to be discarded andthey may remain stored at the document storage means 222.

As explained above, the second embodiment of the present inventionprovides a printing device and a printing method that allow only a partyauthorized to output electronic document data to retrieve the printedmatter. In addition, the information indicating the print retriever IDof the party who has retrieved the printed matter, superimposed on theoutput printed matter, works as an effective deterrent to informationleaks via the printed matter.

While the invention has been particularly shown and described withrespect to preferred embodiments thereof by referring to the attacheddrawings, the present invention is not limited to these examples and itwill be understood by those skilled in the art that various changes inform and detail may be made therein without departing from the spirit,scope and teaching of the invention.

The present invention may be adopted in a printing device and printingmethod with which an electronic document having superimposed thereuponwatermark information is printed.

1. A printing device that prints out electronic document data havingsuperimposed thereupon watermark information, wherein: the printingdevice is configured to receive electronic document data, which weregenerated at a data transmission instruction issuer terminal operated bya data transmission instruction issuer who has issued an instruction fortransmitting an electronic document, and to receive a data transmissioninstruction issuer information to identify the data transmissioninstruction issuer, from the data transmission instruction issuerterminal, the printing device further comprising: a document storageunit for storing the electronic document data; an operating unit at theprinting device for accepting specific information of a print retrieverbased on a user operation; a watermark information superimposing unitfor generating a watermark including the data transmission instructionissuer information and the specific information of the print retrieverhaving been accepted at the operating unit and superimposing thewatermark onto the electronic document data stored at the documentstorage unit; and a printing unit for outputting the electronic documentdata having the watermark superimposed thereupon by the watermarkinformation superimposing unit onto paper as printed matter, wherein: ifthe specific information of the print retriever is not accepted within apredetermined length of time via the operating unit, the electronicdocument data stored at the document storage means are discarded; andthe watermark information superimposing unit superimposes watermarkinformation indicating the data transmission instruction issuerinformation and the specific information of the print retriever over theelectronic document data only after the operating unit accepts thespecific information.
 2. A printing device according to claim 1,wherein: the operating unit waits in standby without accepting thespecific information of the print retriever until after the electronicdocument data are transmitted from the data transmission instructionissuing terminal and the electronic document data are stored into thedocument storage unit.
 3. A printing device according to claim 2,wherein: information indicating a hierarchical attribute of the datatransmission instruction issuer is appended to the electronic documentdata together with the data transmission instruction issuer information,and the print retriever is only authorized to retrieve the electronicdocument data if the print retriever has a hierarchical attribute of atleast equal order to the hierarchical attribute of the data transmissioninstruction issuer.
 4. A printing device according to claim 2, wherein:only after the operating means accepts the specific information, adecision unit makes a decision as to whether or not a personcorresponding to the specific information is authorized to output theelectronic document data onto paper as printed matter, wherein: thewatermark information superimposing unit superimposes the datatransmission instruction issuer information and the specific informationover the electronic document data as a watermark only after the personcorresponding to the specific information is judged to be authorized tooutput the electronic document data onto paper as printed matter.
 5. Aprinting device according to claim 2, wherein: the operating unitcomprises a card reader.
 6. A printing device according to claim 2,wherein: the operating unit comprises a device that executes biometricverification.
 7. A printing method to be adopted in a printing device,comprising steps for: generating electronic document data at a datatransmitting instruction issuing terminal operated by a datatransmitting instruction issuer who has issued an instruction fortransmitting an electronic document, the electronic document datacontaining a data transmitting instruction issuer information: storingthe electronic document data; accepting at the printing device, which isremote from the data transmitting instruction issuing terminal, specificinformation of a print retriever to retrieve the electronic documentdata from the printing device, based on a user operation; generating awatermark including the data transmitting instruction issuer informationand the specific information of the print retriever having been acceptedat the printing device; superimposing the watermark indicating the printinstruction issuer information and the specific information of the printretriever onto the electronic document data at the printing device onlyafter the specific information is accepted at the printing device; andoutputting the electronic document data having superimposed thereuponthe watermark onto paper as printed matter at the printing device,wherein: if the specific information of the print retriever is notaccepted at the printing device within a predetermined length of time,the stored electronic document data are discarded.
 8. A printing methodto be adopted in a printing device according to claim 7, wherein:information indicating a hierarchical attribute of the data transmissioninstruction issuer is appended to the electronic document data togetherwith the data transmission instruction issuer information, and the printretriever is only authorized to retrieve the electronic document data ifthe print retriever has a hierarchical attribute of at least equal orderto the hierarchical attribute of the data transmission instructionissuer.
 9. A printing method to be adopted in a printing deviceaccording to claim 7, further comprising steps for: making a decision asto whether or not a person corresponding to the specific information isauthorized to retrieve the electronic document data from the printingdevice only after the specific information is accepted, wherein:superimposing the watermark onto the electronic document data at theprinting device only if the person corresponding to the specificinformation accepted at the printing device is judged to be authorizedto retrieve the electronic document data from the printing device.
 10. Aprinting method to be adopted in a printing device according to claim 7,wherein: the step of accepting is performed by a card reader.
 11. Aprinting method to be adopted in a printing device according to claim 7,wherein: the step of accepting is performed by a device that executesbiometric verification.
 12. A printing device that prints out electronicdocument data having superimposed thereupon watermark information,wherein: the printing device is configured to receive electronicdocument data, which were generated at a data transmission instructionissuer terminal operated by a data transmission instruction issuer whohas issued an instruction for transmitting an electronic document, andto receive a data transmission instruction issuer information toidentify the data transmission instruction issuer, from the datatransmission instruction issuer terminal, the printing device furthercomprising: a document storage unit for storing the electronic documentdata; an operating unit at the printing device for accepting specificinformation of a print retriever based on a user operation; a watermarkinformation superimposing unit for generating a watermark including thedata transmission instruction issuer information and the specificinformation of the print retriever having been accepted at the operatingunit and superimposing the watermark onto the electronic document datastored at the document storage unit; and a printing unit for outputtingthe electronic document data having the watermark superimposed thereuponby the watermark information superimposing unit onto paper as printedmatter, wherein: the watermark information superimposing unitsuperimposes watermark information indicating the data transmissioninstruction issuer information and the specific information of the printretriever over the electronic document data only after the operatingunit accepts the specific information.
 13. A printing device accordingto claim 12, wherein: the operating unit waits in standby withoutaccepting the specific information of the print retriever until afterthe electronic document data are transmitted from the data transmissioninstruction issuing terminal and the electronic document data are storedinto the document storage unit.
 14. A printing device according to claim13, wherein: if the specific information of the print retriever is notaccepted within a predetermined length of time via the operating unit,the electronic document data stored at the document storage means arediscarded.
 15. A printing device according to claim 13, wherein:information indicating a hierarchical attribute of the data transmissioninstruction issuer is appended to the electronic document data togetherwith the data transmission instruction issuer information, and the printretriever is only authorized to retrieve the electronic document data ifthe print retriever has a hierarchical attribute of at least equal orderto the hierarchical attribute of the data transmission instructionissuer.
 16. A printing device according to claim 13, wherein: only afterthe operating means accepts the specific information, a decision unitmakes a decision as to whether or not a person corresponding to thespecific information is authorized to output the electronic documentdata onto paper as printed matter, wherein: the watermark informationsuperimposing unit superimposes the data transmission instruction issuerinformation and the specific information over the electronic documentdata as a watermark only after the person corresponding to the specificinformation is judged to be authorized to output the electronic documentdata onto paper as printed matter.
 17. A printing device according toclaim 13, wherein: the operating unit comprises a card reader.
 18. Aprinting device according to claim 13, wherein: the operating unitcomprises a device that executes biometric verification.